A round black coaster is a small, flat disc-shaped object, which is placed under a drinking glass or cup to protect the surface of a table or other furniture from water rings or spills. The coaster is circular in shape and has a solid black color, giving it a sleek and minimalist appearance. Its surface is smooth to provide a non-slip grip for the glass or cup. The edges include a stitching ornamentation, adding to the coaster's aesthetic appeal. Overall, a round black coaster is a functional and stylish accessory that is perfect for any home or office setting.